At many locations access is restricted by access control mechanisms, in particular lock mechanisms for locking doors or other access points. Often, access to residential or commercial buildings involves unlocking a plurality of doors such as an outer or front door, an elevator door, a door to a specific part of a building e.g. to a level or floor before getting to a point of service, such as an apartment door, a mailbox, a service station or a meter for appliances, an area to be cleaned, etc.
For example, in case of delivery of newspapers, the delivery person often has to gain access to a stairway in order to be able to deliver the newspapers at a locked apartment door or to put the newspaper into a mail box. Finding the correct keys in a large bundle of physical keys frequently causes great difficulties to the delivery person, and the locks are frequently exchanged without the delivery company being informed of this. For reasons of security it is also more and more common to lock doors or gates to backyards, residential areas or company properties, where for example refuse containers may be placed, so that the refuse collection firms have a problem quite similar to the firms that deliver newspapers. It will be appreciated that similar problems are faced by postal delivery personal, cleaning companies, emergency physicians, domestic and other care workers, policemen, firemen, artisans, caretakers/superintendents, etc.
Some of the above service providers require access on a daily basis, while others may require access at certain time periods, such as on certain weekdays or at certain times of the day. Furthermore, different services/deliveries may require different access rights, for example firemen, security companies or police may require access to all facilities, while a mailman only requires access to a mailbox.
In order to facilitate flexible and secure management of access rights electronic access control systems exist. In particular, mobile telephones or similar mobile units have been suggested as advantageous carriers of electronic keys, since no physical keys are necessary with such systems. This means that the disadvantage of using physical keys, where keys are easily lost and difficult to find in a large bundle of keys may be overcome. Furthermore, it is very easy to prohibit access to a lock control unit, when the key to this lock control unit is an electronic key, because the access request for obtaining access with an electronic is easy to deny.
US2002180582 discloses an efficient method and a system for controlling access to a location secured by a lock mechanism controlled by a lock control unit, which may provide a high degree of flexibility and a high level of security. This prior art method comprises storing electronic access codes in the lock control unit, and using an electronic key device for requesting access to the location by transmitting a corresponding access code from the electronic key device to the lock control unit. The lock control unit may then compare the transmitted access code with the previously stored access code. The lock control unit activates the lock mechanism only if the access codes match.
EP2085934 discloses a method of controlling access to a location secured by a lock mechanism controlled by a lock control unit comprising means for wireless communication with a mobile unit. The mobile unit of this prior art performs the following steps: storing an electronic key in the mobile unit, the electronic key being indicative of a predetermined access right to the location; automatically searching for the lock control unit of the location, when the mobile unit is in a distance from the lock control unit, where wireless communication between the mobile unit and the lock control unit is established; automatically establishing a connection to the lock control unit; automatically transmitting the electronic key wirelessly to the lock control unit; and causing operation of the lock mechanism controlled by the lock control unit, whereby access to the location is obtained.
The above prior art methods and systems greatly improve the efficiency and security of managing and enforcing access rights of a large number of users and to a large number of locations. However, such systems involve challenges as regards convenience of use, security, and cost of implementation and installation. For example, such a system may require a large number of users to be equipped with their respective mobile units. The user mobile units may be special purpose devices, specifically manufactured for use in a lock control system. This allows an operator of the system to maintain control of which users are equipped with mobile units as well as strict control with the devices themselves. It is a considerable disadvantage of such a system, however, that the users are required to carry an additional electronic device. Furthermore, such a solution increases the costs of manufacturing and operating such a system considerably.
It is thus desirable to provide a secure yet convenient and cost-efficient access control system.